EFFECT OF CHARGE–PLASMON INTERACTION TO THE EFFECTIVE MASS OF A CHARGED PARTICLE IN SOLIDS

We use Feynman variational path integral method to study the effective mass of a charged particle in solids in which plasmons are an elementary excitation. This approach has an advantage as the ground state energy and the effective mass can be expressed analytically. We examine a particular case, i.e. the motion of a slow positron in metals. We find that the effective mass increases with rs. The results are compared with those of a similar approach and of experiments. Nevertheless, the effect of the charge–plasmon interaction cannot fully account for the large positron effective mass in metals. The discrepancies are discussed.